540HP NA 7L V12 3 seater
Discussion
A really odd behaviour that this car will display when revving in neutral will be torque cancellation due to the counter rotating engines. Revving should not produce rocking on the engine mounts, which is fairly unique but has no advantage.
However when a gear is engaged and torque applied to the rear axle then the pinions will try to climb around the crownwheel and the engine mounts at the extremities of the engines will have to react the forces. The plenums (sectioned in the view above) will rise and fall respectively but have enough clearance under the rear quarter windows to allow for full torque deflection on the mounts.
Planning to detail a control flap to draw in hot air from the exhaust heat shield below the inlet tract into the airbox to assist with alpine morning starting and warm up, all other times will be drawing cold air from the roof scoop. Air filters, throttle bodies and bow wave deflectors not detailed yet.
The hidden fuel cap can be seen under the left flank panel, will soon have a bracket mounting the flange to the spaceframe. It is higher than the top of the tank so might even be able to squeak an extra litre of fuel into the fill tube.
Edited by F1natic on Wednesday 17th February 10:48
That plenum looks nice - mmmmm carbon fibre! I work with composites so can appreciate how much effort went into that plenum.
PAUL500 said:
Warren, out of interest did you used to have a Puma Cosworth and frequent Passionford back in the day?
Yes indeedy, that is me. Sold it back in 2014/5 IIRC. Was thinking of making it a track car but with the 4x4 running gear being at its limit at 380/380 it would have been silly money to make it strong and reliable but with no extra power. F1natic said:
The hidden fuel cap can be seen under the left flank panel, will soon have a bracket mounting the flange to the spaceframe. It is higher than the top of the tank so might even be able to squeak an extra litre of fuel into the fill tube.
Will you have to build a bulkhead around the fuel tank and filler pipework? I know in some countries they can be a bit fussy about fuel tanks and fill pipework being in engine bay. Psycho Warren said:
That plenum looks nice - mmmmm carbon fibre! I work with composites so can appreciate how much effort went into that plenum.
Ah that was going to be my next question, as I have bought quite a bit of composite materials from you in recent years then.PAUL500 said:
Warren, out of interest did you used to have a Puma Cosworth and frequent Passionford back in the day?
Yes indeedy, that is me. Sold it back in 2014/5 IIRC. Was thinking of making it a track car but with the 4x4 running gear being at its limit at 380/380 it would have been silly money to make it strong and reliable but with no extra power. I was Paul S on PF, I built the brand new 3dr Cosworth back then.
Psycho Warren said:
Will you have to build a bulkhead around the fuel tank and filler pipework? I know in some countries they can be a bit fussy about fuel tanks and fill pipework being in engine bay.
Oddly not. As long as there is a drain for any overfill spillage at the filler cap that exits outside the bodywork, a heat shield from any exhaust, adequate drainage for possible leakage from the tank & no leakage that could ever end up on hot exhaust or an electrical systems then not an issue. But that's the point of completing the layout in detail so that I only have to build it once.Given your experience with composites, do you have a feel for the thickness of laminate that would be adequate for the outer skin panels for this car given they are not truly load bearing but acting as membrane panels? CFRP preferably, but S glass is also very attractive for the toughness.
Have been playing around with the final assemblies and require 100mm minimum of lift to separate the rear engine section. Unfortunately the plenum chambers now clash with the frame during extraction so will have to remove them first through the engine hatch. Need to make a little "taildragger" trolley that fits onto the engine mount so that the whole rear subassembly can be rolled out and about easily. Since the steering is not power assisted both engines can have steering pump position on the accessory belt reassigned to run the oil scavenge pumps - as long as the torque required to run those is within the belts capacity (TBD). The standard J35 oil pump pickup tube is replumbed to take it's feed directly from the oil tank.
Edited by F1natic on Thursday 18th February 10:18
Warren may be to modest to mention it, but you will find him and a load of other like minded people helping out those new to composites here:-
http://www.talkcomposites.com/
Its a great forum, I get lost for days just reading the old posts.
http://www.talkcomposites.com/
Its a great forum, I get lost for days just reading the old posts.
Currently detailing the undertray and sorting the cabin sealing in the footbox. Varying the internal panels to suit assembly method and mounting of the steering rack. The rack mounting bolts will be visible from the drivers seat and have Nordlock washers under their heads (Nordlocks will be specified in other critical positions like the subframe connections) and bolts marked with paint after torquing so it's easy to do a quick visual check.
Unfortunately the rear lower control arm interferes with the diffuser section - once the rolling chassis test mule is running might create a CFD model of the body to get analysis done before committing to the final configuration.
While checking FARB clearance took a snap shot of the turning circle which only has to be under 25m (82ft) diameter to comply.
Unfortunately the rear lower control arm interferes with the diffuser section - once the rolling chassis test mule is running might create a CFD model of the body to get analysis done before committing to the final configuration.
While checking FARB clearance took a snap shot of the turning circle which only has to be under 25m (82ft) diameter to comply.
Turns out the XBOX 360 Kinect scanner setup I wired up a few months ago did work, I just needed to install the drivers correctly on the laptop. Initial tests on the die cast aluminium parts were not good, so had to spray the surface to reduce reflectivity using Ardrox 9D1B developer (basically talc powder in spray form). AESUB makes some very clever spray that evaporates after a day, which avoids the mess I have created on the transmission adaptor plate.
Reusing an old 12V 1.5A power supply, cutting off the Kinect plug and wiring to a USB has produced a working scanner for $2 NZD ~ 1 GBP - the local games shop was selling its old stock of series 1 xbox kinect units - I have enough spare for the next decade.
The scan is not industrial quality - only using Reconstructme free version, and will try out a few others like Skanect - but encouraging results. Really want to scan the entire engine and trans, but not keen to spray them in talcum powder.
Christmas came early today - now have access to a Modix Big60 printer (600 x 600 x 600 build volume) which will be ideal for making the t-box component patterns in 1 piece.
Reusing an old 12V 1.5A power supply, cutting off the Kinect plug and wiring to a USB has produced a working scanner for $2 NZD ~ 1 GBP - the local games shop was selling its old stock of series 1 xbox kinect units - I have enough spare for the next decade.
The scan is not industrial quality - only using Reconstructme free version, and will try out a few others like Skanect - but encouraging results. Really want to scan the entire engine and trans, but not keen to spray them in talcum powder.
Christmas came early today - now have access to a Modix Big60 printer (600 x 600 x 600 build volume) which will be ideal for making the t-box component patterns in 1 piece.
F1natic said:
Given your experience with composites, do you have a feel for the thickness of laminate that would be adequate for the outer skin panels for this car given they are not truly load bearing but acting as membrane panels? CFRP preferably, but S glass is also very attractive for the toughness.
Its hard to say exactly as so many factors at play. A very simple race car might use 1 layer of fabric either side of a 2 or 3mm foam core. A similar road spec version would be 2 layers each side of the core.In solid laminate you might need 1-1.5mm for it to be reasonably stiff.
Flatter panels a bit more - or a foam core for added stiffness, very curvy panels less layers as the curved shape adds a lot of stiffness.
Also consider doors, boot, hood etc are likely to have an inner frame which will help with stiffness too.
I would consider a layer of Aramid fibre in the layup around the safety cell so in an impact, the carbon fibre cannot splinter and fly around the cabin. The aramid holds it together as well as offering a level of impact resistance.
Thanks Warren, carbon shards in the eyes does not sound like fun, I very much appreciate your sage advice. I intend to build some components a few times (like the doors) as experience has shown the best way to get things right first time is to build them at least twice beforehand .
Edited by F1natic on Thursday 11th March 20:05
Found some GTR restrictors that feed into those inlet plenums for sale, I know you guys like seeing that sort of thing
https://www.racecarsdirect.com/Advert/Details/1195...
https://www.racecarsdirect.com/Advert/Details/1195...
Z06 Corvette fuel pump has arrived from Rockauto - but unfortunately it is only 380mm long, which has killed a bit of capacity in the fuel tank with the current simple and symmetrical design, going to have to add odd wings to it to get back to 65 litre capacity. The tank is not in view so its OK if it is a bit ugly.
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